Refrigerator

ABSTRACT

A refrigerator ( 1 ) having a temperature switchable compartment ( 3 ) whose interior temperature can be switched among more than one alternatives is provided with: a cooling device ( 17 ) for producing cold air; a blower ( 14 ) for sending out the cold air produced by the cooling device ( 17 ) into the temperature switchable compartment ( 3 ); a temperature switchable compartment discharge damper ( 13 ) for opening and closing an air introduction path ( 12 ) through which the cooling device ( 17 ) communicates with the blower ( 14 ); and a temperature switchable compartment return damper ( 20 ) for opening and closing an air return path ( 19 ) through which an outlet port ( 33   b ), from which air in the temperature switchable compartment ( 3 ) flows out, communicates with the cooling device ( 17 ) and opens and closes a communication path ( 36 ) through which the outlet port ( 33   b ) communicates with the inlet side of the blower ( 14 ). When the communication path ( 36 ) is closed and the air return path ( 19 ) is opened by the temperature switchable compartment return damper ( 20 ) and the blower ( 14 ) is driven after the temperature switchable compartment discharge damper ( 13 ) is opened, cold air is introduced into the temperature switchable compartment ( 3 ). When the communication path ( 36 ) is opened and the air return path ( 19 ) is closed by the temperature switchable compartment return damper ( 20 ) and the blower ( 14 ) is activated after the temperature switchable compartment discharge damper ( 13 ) is closed, the air in the temperature switchable compartment ( 3 ) is circulated. In the temperature switchable compartment discharge damper ( 13 ), a baffle ( 42 ) is arranged closer to the cooling device ( 17 ) than an opening ( 40   a ) is, so that the baffle ( 42 ) is swingable even if moisture condensation occurs on the baffle ( 42 ) and the condensed water freezes.

TECHNICAL FIELD

The present invention relates to a refrigerator having a temperatureswitchable compartment whose interior temperature can be switched to adesired one by the user. The present invention also relates to arefrigerator including a damper for opening and closing a cold air path,the damper being provided at the cold air inlet side of a storagecompartment.

BACKGROUND ART

Patent Publication 1 discloses a refrigerator provided with atemperature switchable compartment in addition to a freezer compartmentand a cooling compartment. This refrigerator includes: a damper devicefor opening and closing a cold air path through which cold air issupplied to the temperature switchable compartment; and a heater forraising the interior temperature of the temperature switchablecompartment. This makes it possible for the user to switch the interiortemperature of the temperature switchable compartment, according to thepurpose for which he/she uses it, to a desired low temperature zoneamong, for example, those intended for freezing, cooling, partialfreezing, and chilling.

[Patent Publication 1] JP-A-H10-288440 DISCLOSURE OF THE INVENTIONProblems to be Solved by the Invention

One disadvantage with the conventional refrigerator described above isthat since the interior temperature of the temperature switchablecompartment is changed through the adjustment, using a damper device, ofthe amount of cold air flowing from a cooling device into thetemperature switchable compartment, if there is a large differencebetween the temperature of the cold air flowing into the temperatureswitchable compartment and the preset temperature, it is not possible toproduce an even temperature distribution. Another disadvantages is thatwhen a heater is energized in an airtight condition, the temperaturearound the heater rises, making it impossible to produce an eventemperature distribution.

An object of the present invention is to provide a refrigerator that canproduce an even temperature distribution in a temperature switchablecompartment.

Means for Solving the Problem

To achieve the above object, according to one aspect of the presentinvention, a refrigerator including a temperature switchablecompartment, whose interior temperature can be switched among more thanone alternatives, is provided with: a cooling device for producing coldair; a blower for sending the cold air produced by the cooling deviceinto the temperature switchable compartment; an introduction gate foropening and closing an air introduction path through which the coolingdevice communicates with the blower; a return gate for opening andclosing an air return path through which the cooling device communicateswith an outlet port through which air flows out of the temperatureswitchable compartment; and a circulation gate for opening and closing acommunication path through which a circulation port formed in thetemperature switchable compartment communicates with an inlet side ofthe blower. Here, when the introduction gate and the return gate areopened, the circulation gate is closed, and when the circulation gate isopened, the introduction gate and the return gate are closed.

With this structure, when the blower is operated with the circulationgate closed and the introduction gate and the return gate open, the coldair produced by the cooling device is sent into the temperatureswitchable compartment through the air introduction path. The cold airflows through the temperature switchable compartment, through the outletport, and flows back to the cooling device through the air return path.The temperature switchable compartment is cooled in this way, and byvarying the degrees to which the introduction gate and the return gateare opened or the amount of air supplied from the blower, the interiortemperature of the temperature switchable compartment can be switched todifferent internal temperatures such as a freezing, a partial freezing,a chilling, and a cooling temperature. On the other hand, when theblower is operated with the circulation gate open and with theintroduction gate and the return gate closed, the air inside thetemperature switchable compartment is led out thereof via thecirculation port through the communication path to the inlet side of theblower, and is then sent into the temperature switchable compartment.Thus, the air inside the temperature switchable compartment iscirculated.

According to the present invention, in the refrigerator structured asdescribed above, a heater may be provided for raising the interiortemperature of the temperature switchable compartment so as to switch itto the hot setting for keeping cooked food warn. With this structure,when the setting for the temperature switchable compartment is switchedto the hot setting, the circulation gate is opened, and the introductiongate and the return gate are closed. Then, the blower and the heater areoperated so as to raise the interior temperature of the temperatureswitchable compartment. This makes temporary storage of cooked food,warm storage of food for cooking purposes in winter, and the likepossible.

According to the present invention, the heater provided in therefrigerator structured as described above may be a heat-radiatingglass-tube heater arranged so as to face the blower.

According to the present invention, in the refrigerator structured asdescribed above, a single temperature switchable compartment returndamper may be shared to serve as both the return gate and thecirculation gate; a single opening may be formed to serve as both theoutlet port and the circulation port so that the return path and thecommunication path extending from the opening branch off each other atthe temperature switchable compartment damper; and the temperatureswitchable compartment return damper may have a double-sided baffle thatswings between a position in which the baffle interrupts thecommunication path and a position in which the baffle interrupts the airreturn path.

With this structure, the temperature switchable compartment returndamper having the swingable double-sided baffle is shared to serve asboth the return gate and the circulation gate, and when the double-sidedbaffle closes the air return path, the communication path is opened. Inthis state, when the blower is operated with the temperature switchablecompartment discharge damper closed, the air inside the temperatureswitchable compartment is led out thereof via the opening through thecommunication path to the inlet side of the blower, and thus the air iscirculated. When the communication path is closed by the double-sidedbaffle, the air return path is opened. In this state, when the blower isoperated with the temperature switchable compartment discharge damperopen, the cold air produced by the cooling device flows into thetemperature switchable compartment through the air introduction path,through the opening, and then back to the cooling device through the airreturn path.

According to the present invention, in the refrigerator structured asdescribed above, the double-sided baffle may be swingably supported by apivot shaft extending horizontally along a top end of the double-sidedbaffle. With this structure, when the double-sided baffle closes the airreturn path and condensation occurs on the double-sided baffle due to atemperature difference between the temperature switchable compartmentside and the cooling device side, the condensed water runs down, awayfrom the horizontally extending pivot shaft.

According to the present invention, a single damper may be shared toserve as both the introduction gate and the circulation gate; the airintroduction path and the communication path may join at the damper soas to be led to the inlet side of the blower; and the damper may have adouble-sided baffle that swings between a position inn which the bafflecloses the communication path and a position in which the baffle closesthe air introduction path.

With this structure, a single damper having a swingable double-sidedbaffle is shared to serve as both the introduction gate and thecirculation gate, and when the air introduction path is closed by thedouble-sided baffle, the communication path is opened. In this state,when the blower is operated with the air return gate closed, the airinside the temperature switchable compartment is led out thereof via theopening through the communication path, and to the inlet side of theblower, and thus the air is circulated. When the communication path isclosed by the double-sided baffle, the air introduction path is opened.In this state, when the blower is operated with the air return pathopen, the cold air produced by the cooling device flows into thetemperature switchable compartment through the air introduction path,through the opening, and back to the cooling device through the airreturn path.

According to the present invention, in the refrigerator structured asdescribed above, the introduction gate may be a temperature switchablecompartment discharge damper, and the temperature switchable compartmentdischarge damper may have an opening that communicates with thetemperature switchable compartment and a movable baffle for opening andclosing the opening that is arranged on the cooling device side of theopening.

With this structure, when the blower is operated with the circulationgate closed and with the temperature switchable compartment dischargedamper and the return gate open, the cold air produce by the coolingdevice is sent into the temperature switchable compartment through theair introduction path. The cold air flows through the temperatureswitchable compartment, through the outlet port, and then back to thecooling device through the air return path. In this way, the temperatureswitchable compartment is cooled, and according to the degrees to whichthe discharge damper of the temperature switchable compartment and thereturn gate are opened or according to the amount of the air suppliedfrom the blower, the interior temperature of the temperature switchablecompartment can be switched among, for example, those intended forfreezing, partial freezing, chilling, and cooling. When the blower isoperated with the circulation gate open and with the temperatureswitchable compartment discharge damper and the return gate closed, theair inside the temperature switchable compartment is led through thecirculation port, via the communication path, and to the inlet side ofthe blower, and is then sent into the temperature switchablecompartment. Thus, the air inside the temperature switchable compartmentis circulated. The temperature-switchable compartment discharge damperis disposed in the air introduction path, and the temperature switchablecompartment communicates with the cooling device via the opening. Theopening is opened and closed by the movable baffle disposed on thecooling device side of the opening.

According to the present invention, in the refrigerator structured asdescribed above, there may be provided a heater for raising the interiortemperature of the temperature switchable compartment so that, byoperating the heater, the interior temperature of the temperatureswitchable compartment can be switched to the hot setting for keepingcooked food warm. With this structure, when the setting for thetemperature switchable compartment is switched to the hot setting, thecirculation gate is opened, and the temperature switchable compartmentdischarge damper and the air return gate are closed. Then, the blowerand the heater are operated so as to raise the interior temperature ofthe temperature switchable compartment. This allows temporary storage ofcooked food, warm storage of food for cooking purposes in winter, andthe like.

According to another aspect of the present invention, in a refrigeratorin which the cold air produced by a cooling device is supplied to astorage compartment through a cold air path, a damper for varying theamount of cold air supplied to the storage compartment is disposed inthe cold air path; and the damper has an opening that communicates withthe storage compartment and a movable baffle that opens and closes theopening and that is arranged on the cooling device side of the opening.With this structure, the cold air produced by the cooling device issupplied to the storage compartment through the cold air path, and thusthe storage compartment is cooled. The damper is disposed in the coldair path, and the storage compartment communicates with the coolingdevice via the opening. The opening is opened and closed by the movablebaffle arranged on the cooling device side of the opening.

According to the present invention, in the refrigerator structured asdescribed above, the storage compartment may be a temperature switchablecompartment whose interior temperature can be switched among more thanone alternatives; and there may be provided a cooling compartment thatis arranged in parallel with the storage compartment and to which coldair is supplied through a path that branches off the cold air path.

According to the present invention, in the refrigerator structured asdescribed above, the baffle may be supported by a pivot shafthorizontally extending along the top end of the baffle. With thisstructure, when a path through which cold air is supplied to a storagecompartment such as a temperature switchable compartment is closed bythe baffle and a temperature difference arises between the storagecompartment side and the cooling device side, causing condensation onthe baffle, the condensed water runs down, away from the horizontallyextending pivot shaft.

According to the present invention, in the refrigerator structured asdescribed above, a heat insulator may be provided on a surface of thebaffle.

According to the present invention, in the refrigerator structured asdescribed above, at a rim of the opening, at a side thereof oppositefrom the baffle, there may be formed a step lower than the opening or aslope slanting downward from the rim of the opening. With thisstructure, when condensation occurs on the side of the baffle oppositefrom the cooling device side, the condensed water runs down the baffleand is led to the storage compartment (e.g., a temperature switchablecompartment) side via the step or the slope.

ADVANTAGES OF THE INVENTION

According to the present invention, a refrigerator is provided with ablower for sending cold air, an introduction gate for opening andclosing an air introduction path, a return gate for opening and closingan air return path, and a circulation gate for opening and closing acommunication path through which a circulation port formed in atemperature switchable compartment communicates with the inlet side ofthe blower. Here, when the circulation gate is opened, the introductiongate and the return gate are closed, and this allows the air inside thetemperature switchable compartment in an airtight state to be circulatedtherein, making it possible to produce an even temperature distributioninside the temperature switchable compartment. The circulation gate isclosed when the introduction gate and the return gate are opened, andhence the cold air flows through the temperature switchable compartment,and this makes it possible to produce an even temperature distributioninside the temperature switchable compartment. At this time, since thecirculation gate is closed, it is possible to prevent the efficiency ofthe blower from decreasing.

According to the present invention, a heater is provided for raising theinterior temperature of the temperature switchable compartment and theinterior temperature of the temperature switchable compartment can beswitched to the hot setting for keeping heated food hot by operating theheater, and hence, it is possible to provide a refrigerator that iseconomical to the user by eliminating the need for a separatewarm-keeping box or the like for keeping cooked food warm and that isuseful by eliminating the need for securing a space for such awarm-keeping box or the like. It is also possible to prevent the heaterand the components around it from deforming, burning, or smoking.

According to the present invention, the heater is a heat-radiatingglass-tube heater having a high heating rate arranged so as to face theblower, and this allows the interior temperature of the temperatureswitchable compartment to quickly pass through the temperature range inwhich food poisoning microorganisms grow. Therefore, it is possible toprovide a refrigerator which is safe in terms of food hygiene.Furthermore, even a high-capacity heat-radiating glass-tube heateroccupies a small space, and hence the heater can be disposed in a rearportion of the temperature switchable compartment, and this reduces therisk of the user getting burned. Moreover, the surface temperature ofthe heater can be lowered, thereby improving the safety.

According to the present invention, a single temperature switchablecompartment return damper is shared to serve as both the return gate andthe circulation gate, and a swingable double-sided baffle selectivelycloses one of the communication path and the air return path at a time,and this reduces the cost of the refrigerator and improves the volumeefficiency thereof.

According to the present invention, the double-sided baffle is supportedby a pivot shaft horizontally extending along the top end of thedouble-sided baffle, and hence, when a temperature difference arisesbetween the storage compartment side and the cooling device side of thedouble-sided baffle, causing condensation on the double-sided baffle,the condensed water runs down, away from the pivot shaft. This preventsthe pivot shaft from being frozen up even if the condensed water freezeswhen the opening is opened, permitting the double-sided baffle to movenormally. This also helps prevent the swinging movement of thedouble-sided baffle from being hampered by the condensed water that hasdripped down from the double-sided baffle to freeze in a heap.

According to the present invention, a single damper is shared to serveas both the introduction gate and the circulation gate, and theswingable double-sided baffle selectively closes one of thecommunication path and the air return path at a time. This reduces thecost of the refrigerator and improves the volume efficiency thereof.

According to the present invention, in the temperature switchablecompartment discharge damper disposed in the air introduction path, abaffle for opening and closing the opening is located on the coolingdevice side of the opening, and thus, when the baffle closes theopening, only the portion thereof showing through the rim of the openingis exposed to the temperature switchable compartment side, whosetemperature is higher than that of the cooling device side. Hence, whena temperature difference exists between the cooling device side and thetemperature switchable compartment side, condensation occurs only on theportion of the baffle showing through the rim of the opening but not onthe pivot shaft of the baffle or other portions thereof. Therefore, evenwhen the opening is opened and the condensed water meets the cold air tofreeze, the normal movement of the baffle is not hampered, and thusundercooling and overcooling of the temperature switchable compartmentcan be prevented.

According to the present invention, since, in the damper disposed in thecold air path, the baffle for opening and closing the opening isdisposed on the cooling device side of the opening, when the bafflecloses the opening, only the portion of the baffle showing through therim of the opening is exposed to the storage compartment side, whosetemperature is higher than that of the cooling device side. Hence, whena temperature difference exists between the cooling device side and thestorage compartment side, condensation occurs only on the portion of thebaffle showing through the rim of the opening but not on the pivot shaftof the baffle or other portions thereof. Therefore, when the opening isopened and the condensed water meets cold air to freeze, the normalmovement of the baffle is not hampered, and thus undercooling andovercooling of the storage compartment can be prevented.

According to the present invention, the baffle is supported by a pivotshaft horizontally extending along the top end of the baffle. Thus, whena temperature difference arises between the temperature switchablecompartment side and the cooling device side of the baffle andcondensation occurs on the baffle, the condensed water runs down, awayfrom the pivot shaft. Hence, even when the opening is opened and thecondensed water meets cold air to freeze, it is possible to prevent thepivot shaft from being frozen up, and thereby to permit the baffle tomove normally. It is also possible to prevent the swinging movement ofthe baffle from being hampered by the freezing of the condensed waterthat has dripped from the baffle.

According to the present invention, a heat insulator is provided on asurface of the baffle, and this reduces condensation on the baffle.

According to the present invention, around the rim of the opening at theside of the opening opposite from the baffle, there is formed a steplower than the opening or a slope slanting downward from the rim of theopening. Hence, when condensation occurs on the baffle and the condensedwater runs down, the condensed water is led from the rim of the openingdown to the step or along the slope to the side opposite from thecooling device. Therefore, it is possible to prevent the condensed waterfrom entering the cooling device side via the opening when the baffle isopened.

According to the present invention, the storage compartment is atemperature switchable compartment whose interior temperature can beswitched among more than one alternatives, and there is provided acooling compartment that is arranged in parallel with the storagecompartment and to which cold air is supplied through a path branchingoff the cold air path. Hence, it is possible to store articles in thecooling compartment either in cold storage or in frozen storage, whileproducing an even temperature distribution inside the temperatureswitchable compartment by keeping it airtight and circulating airtherein.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A front view of a refrigerator embodying the present invention;

FIG. 2 A right side view of the refrigerator embodying the presentinvention;

FIG. 3 A vertical sectional view as seen from the right side of therefrigerator embodying the present invention;

FIG. 4 A vertical sectional view as seen from the right side of atemperature switchable compartment of the refrigerator embodying thepresent invention;

FIG. 5 A vertical sectional view as seen from the right side of thetemperature switchable compartment of the refrigerator embodying thepresent invention;

FIG. 6 A vertical sectional view as seen from the front of a middleportion of the refrigerator embodying the present invention;

FIG. 7 A cold air circuit diagram showing how cold air flows in therefrigerator embodying the present invention;

FIG. 8 Diagrams showing a discharge damper of the temperature switchablecompartment in the refrigerator embodying the present invention;

FIG. 9 A vertical sectional view as seen from the side showing how thedischarge damper of the temperature switchable compartment is fitted inthe refrigerator embodying the present invention;

FIG. 10 A diagram illustrating, by way of a counterexample, the effectof the discharge damper of the temperature switchable compartment of therefrigerator embodying the present invention; and

FIG. 11 A diagram illustrating, by way of a counterexample, the effectof the discharge damper of the temperature switchable compartment of therefrigerator embodying the present invention.

LIST OF REFERENCE SYMBOLS

-   -   1 refrigerator    -   2 cooling compartment    -   3 temperature switchable compartment    -   4 ice-maker compartment    -   5 vegetable compartment    -   6 freezer compartment    -   9 door    -   12 air introduction path    -   13 temperature switchable compartment discharge damper    -   14, 18, 28 blower    -   15 heater    -   17 evaporator    -   16, 24 temperature sensor    -   19, 21 air return path    -   20 temperature switchable compartment return damper    -   22 freezer compartment damper    -   25 chilling compartment damper    -   30 thermal fuse    -   31, 32 cold air path    -   33 rear panel    -   33 a inlet port    -   33 b outlet port    -   35 compressor    -   36 communication path    -   40 housing    -   40 a opening    -   42 baffle    -   42 a pivot shaft    -   43 sealing member

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings. FIGS. 1 and 2 are a front viewand a right side view, respectively, of a refrigerator embodying thepresent invention. A cooling compartment 2 is arranged in a top portionof the refrigerator 1, and a temperature switchable compartment 3 and anice-maker compartment 4 are arranged in a middle portion thereof. In abottom portion of the refrigerator 1, a vegetable compartment 5 and afreezer compartment 6 are arranged.

The cooling compartment 2 has double doors and keeps articles in coldstorage. The temperature switchable compartment 3 is arranged in a leftside of the middle portion of the refrigerator 1 and the interiortemperature of the temperature switchable compartment 3 can be switchedby the user. The ice-maker compartment 4 is arranged in a right side ofthe middle portion of the refrigerator 1 and makes ice. The vegetablecompartment 5 is arranged in a left side of the bottom portion of therefrigerator 1 and the interior temperature thereof is maintained at atemperature suitable for storing vegetables (e.g., 8° C.). The freezercompartment 6 is arranged in a right side of the bottom portion of therefrigerator 1; it communicates with the ice-maker compartment 4, andkeeps articles in frozen storage.

FIG. 3 is a vertical sectional view, as seen from the right side, of therefrigerator 1. The freezer compartment 6 and the ice-maker compartment4 are each provided with a storage case 11. Likewise, the vegetablecompartment 5 and the temperature switchable compartment 3 are eachprovided with a storage case 11. The cooling compartment 2 includes aplurality of storage shelves 41 on which to place stored articles. Thedoors of the cooling compartment 2 have storage pockets 42. These makethe refrigerator 1 handy to use. Inside the cooling compartment 2, in abottom part thereof, a chilling compartment 23 is arranged, and theinterior temperature is maintained within a chilling temperature zone(about −3° C.).

Behind the freezer compartment 6, a cold air path 31 is formed. In thecold air path 31, there is arranged an evaporator 17, which is connectedto a compressor 35. Behind the cooling compartment 2, there is formed acold air path 32 that communicates with the cold air path 31. When thecompressor 35, to which a condenser and an expander (neither isillustrated) are connected, is operated, it circulates a refrigerantsuch as isobutane through a refrigeration cycle and thereby achievesheat exchange with the evaporator 17, which is disposed at the cold endof the refrigeration cycle, where cold air is produced. Thus, thecompressor 35 and the evaporator 17, together with the condenser and theexpander, constitute a cooling device for producing cold air.

In the cold air paths 31 and 32, blowers 18 and 28 are arranged,respectively. As will be described in detail later, when the blower 18is operated, the cold air produced at the evaporator 17 is suppliedthrough the cold air path 31 to the freezer compartment 6, the ice-makercompartment 4, the chilling compartment 23, and the temperatureswitchable compartment 3. Moreover, when the blower 28 is operated, thecold air is also supplied through the cold air path 32 to the coolingcompartment 2 and the vegetable compartment 5.

FIG. 4 is a vertical sectional view, as seen from the right side, of thetemperature switchable compartment 3. The temperature switchablecompartment 3 is, at the top and bottom faces thereof, separated fromthe cooling compartment 2 and the vegetable compartment 5 by partitionwalls 7 and 8, respectively. The temperature switchable compartment 3can be opened and closed at the front face thereof with a pivoted door9. The rear face of the temperature switchable compartment is coveredwith a rear panel 33. Inside the temperature switchable compartment, adrawer-type storage case 11 is provided.

Behind the rear panel 33, between it and a heat insulating wall 10,which constitutes an exterior wall of the refrigerator 1, an airintroduction path 12 is formed. Through the air introduction path 12, aninflow port 33 a formed in the rear panel 33 connects to the cold airpath 31 (see FIG. 3). In the air introduction path 12, a temperatureswitchable compartment discharge damper 13 (introduction gate) isprovided. When the temperature switchable compartment discharge damper13 is opened, the cold air produced at the evaporator 17 (see FIG. 3) isled to the temperature switchable compartment 3.

FIGS. 8A to 8C are a front view, a top view, and a vertical sectionalside view, respectively, of the temperature switchable compartmentdischarge damper 13. The temperature switchable compartment dischargedamper 13 has a baffle 42 provided inside a resin-molded housing 40having an opening 40 a formed in the front face thereof. The baffle 42is swingably supported on a pivot shaft 42 a extending horizontallyalong the top end thereof inside the housing 40.

When a drive motor 41 coupled to the pivot shaft 42 a is driven, thebaffle 42 swings as indicated by arrow H. As the baffle 42 swings, itopens and closes the opening 40 a, and thereby opens and closes thetemperature switchable compartment discharge damper 13. On the baffle42, on the side thereof facing the opening 40 a, there is disposed asealing member 43 that is formed of a heat insulating material and comesinto close contact with the rim of the opening 40 a.

FIG. 9 is a vertical sectional view, as seen from the side, showing howthe temperature switchable compartment discharge damper 13 is fitted.The temperature switchable compartment discharge damper 13 is fitted toa wall 50 of the air introduction path 12. As will be described later,the air introduction path 12 branches in two directions, specifically onone hand in the direction of the temperature switchable compartment 3,which is arranged further leftward of the figure, and on the other hand,in the direction of the chilling compartment 23, which is arrangedfurther upward of the figure. The air introduction path 12 communicateswith the temperature switchable compartment 3 via a hole 50 a. Thetemperature switchable compartment discharge damper 13 is arranged withthe opening 40 a located on the temperature switchable compartment 3side of the baffle 42, and with the baffle 42 located on the evaporator17 side of the opening 40 a (relative to FIG. 9, the temperatureswitchable compartment 3 is situated further leftward and the evaporator17 is situated further rightward).

Since the temperature of the cold air flowing through the airintroduction path 12 is lower than the interior temperature of thetemperature switchable compartment 3, when the baffle 42 closes theopening 40 a, a temperature difference arises between opposite sides ofthe baffle 42. If, as shown in FIG. 10, the baffle 42 is located on thetemperature switchable compartment 3 side of the opening 40 a (i.e.,left in the figure), the baffle 42 becomes hotter except in the portionthereof that shows through the opening 40 a.

This causes condensation on the warmer portion of the baffle 42, and, ifit happens, when the opening 40 a is opened, the condensed water meetscold air and freezes, freezing up the pivot shaft 42 a. If, as a result,the baffle 42 becomes unable to fully open the opening 40 a, theinterior temperature of the temperature switchable compartment 3 isundercooled; if the baffle 42 becomes unable to fully close the opening40 a, the temperature switchable compartment 3 is overcooled.

In contrast, in the present embodiment, the baffle 42 is located on theevaporator 17 side of the opening 40 a; hence, when the opening 40 a isclosed, the baffle 42 becomes hotter only in the portion thereof showingthrough the opening 40 a. In addition, the sealing member 43 formed of aheat insulating material disposed on the surface of the baffle 42prevents condensation. The heat insulator may be disposed on the face ofthe baffle 42 opposite from the opening 40 a.

Even if condensation occurs on the baffle 42, it occurs only on theportion thereof that shows through the opening 40 a, and not on thepivot shaft 42 a of the baffle 42. Therefore, even if the condensedwater freezes when the opening 40 a is opened, the baffle 42 swingsnormally, without causing undercooling or overcooling of the temperatureswitchable compartment 3.

The baffle 42 is particularly prone to condensation of moisture fromstored articles when the internal temperature of the temperatureswitchable compartment 3 is at the hot setting (for example, 55° C. to80° C.), which will be described later. Even then, despite a largeamount of frozen condensed water, the baffle 42 swings normally, withoutcausing undercooling or overcooling of the temperature switchablecompartment 3, and thus with greater effect. Similar benefits can beobtained also in a case where the baffle 42 is a sliding one instead ofa swinging one.

With a similar structure, similar benefits can be obtained also in acase where a damper is arranged for opening and closing a cold air paththrough which cold air is supplied to a storage compartment whose coldair circuit is arranged in parallel with that of another coolingcompartment wherein when the damper is closed, the air in the storagecompartment is circulated inside it. Specifically, by locating a baffleon the evaporator (cooling device) side of an opening in the damper, itis possible to prevent frozen condensed water from hampering the normalmovement of the baffle. Thus, it is possible to prevent undercooling andovercooling of the storage compartment.

Since the pivot shaft 42 a is arranged along the top end of the baffle42, even when condensation occurs on the baffle 42, the condensed waterruns down, away from the pivot shaft 42 a. Hence, even when the opening40 a is opened and the condensed water meets cold air and freezes, thepivot shaft 42 a is prevented more effectively from being frozen up, sothat the baffle 42 swings normally.

If, as shown in FIG. 11, the pivot shaft of the baffle 42 extendsvertically, when the opening 40 a is opened, the condensed water thathas dripped from the baffle 42 freezes in a heap, and this hampers theswinging movement of the baffle 42. By contrast, in the presentembodiment, where the pivot shaft 42 a extends horizontally along thetop end of the baffle 42, when the opening 40 a is opened, the bottomend of the baffle 42 retracts by moving up. This makes it possible toprevent the swinging movement of the baffle 42 from being hampered evenwhen condensed water drips from the baffle 42 and freezes.

Back in FIG. 9, the hole 50 a in the wall 50 is formed to be larger indiameter than the opening 40 a, and a step 50 b is formed at a levellower than the opening 40 a. Thus, the condensed water that has run downthe baffle 42 is diverted from the rim of the opening 40 a into thetemperature switchable compartment 3. This prevents entry of condensedwater through the opening 40 a into the evaporator 17. Instead of thestep 50 b, a slope slanting downward from the rim of the opening 40 amay be formed.

In FIG. 4, a blower 14 is arranged between the temperature switchablecompartment discharge damper 13 and the inlet port 33 a. In a bottomportion of the rear panel 33, an outlet port 33 b is formed, and whenthe blower 14 is activated, cold air is easily introduced from the coldair path 31 into the temperature switchable compartment 3 via the inletport 33 a and then discharged out of the temperature switchablecompartment 3 via the outlet port 33 b. The amount of air supplied fromthe air introduction path 12 to the temperature switchable compartment 3is controlled by opening and closing the temperature switchablecompartment discharge damper 13.

Behind the outlet port 33 b, there is formed an air return path 19through which air returns to the air cooling device 17. In the airreturn path 19, there is formed a temperature switchable compartmentreturn damper 20 (return gate) open to face the outlet port 33 b. In therear and the top of the temperature switchable compartment return damper20, openings 20 b and 20 c are formed, respectively, and inside thetemperature switchable compartment return damper 20, there is arranged adouble-sided swingable baffle 20 a for selectively closing one of theopenings 20 b and 20 c at a time.

When the opening 20 c is closed and the opening 20 b is open, the airthat has flowed out of the outlet port 33 b flows into the air returnpath 19. When the opening 20 b is closed and the opening 20 c is opened,as shown in FIG. 5, the air that has flowed out of the outlet port 33 bis led to the inlet side of the blower 14. In this way, a communicationpath 36 is formed, through which the outlet port 33 b communicates withthe inlet side of the blower 14 via the opening 20 c of the temperatureswitchable compartment return damper 20. Thus, with the blower 14operated, the air in the temperature switchable compartment 3 can becirculated inside it via the communication path 36.

Since the pivot shaft of the baffle 20 a extends horizontally along thetop end thereof, even when a temperature difference arises between theevaporator 17 side and the temperature switchable compartment 3 side ofthe baffle 20 a and condensation occurs on the baffle 20 a, thecondensed water runs down, away from the pivot shaft. Hence, even whenthe condensed water freezes when the opening 20 b is opened, it ispossible to prevent the pivot shaft from being frozen up to ensure thatthe baffle 20 a swings normally. When the baffle 20 a swings, the bottomend thereof retracts by moving up. This prevents the swinging movementof the double-sided baffle 20 a from being hampered by condensed waterthat has dripped therefrom and has frozen in a heap.

The temperature switchable compartment return damper 20 serves as acirculation gate for opening and closing the circulation path thatincludes the communication path 36. The outlet port 33 b serves as acirculation port via which air flows out of the temperature switchablecompartment 3 into the communication path 36. The communication path 36may be formed by arranging the circulation port at a position differentfrom that of the outlet port 33 b. In this case, however, in addition tothe temperature switchable compartment return damper 20, anothercirculation gate for opening and closing the communication path 36 needsto be formed. Hence, with the present embodiment, in which the outletport 33 b is shared as the circulation port and the temperatureswitchable compartment return damper 20 having the double-sided baffle20 a serves as the circulation gate, it is possible to reduce the costof the refrigerator 1 and to improve the volume efficiency thereof.

In a top rear portion of the rear panel 33, a heater 15 is arranged. Theheater 15 is a heat-radiating glass-tube heater, and the heat therefromis radiated through the rear panel 33 to heat the temperature switchablecompartment 3. The blower 14 is arranged such that it sends air towardthe surface of the heater 15. This helps lower the surface temperatureof the heater 15, and thereby improves safety.

On the bottom rear portion of the rear panel 33, a temperature sensor 16is arranged. The temperature sensor 16 detects the interior temperatureof the temperature switchable compartment 3 and sends a detection signalto a controller (not shown). The controller, according to the detectionresult of the temperature sensor 16, controls the heater 15, thetemperature switchable compartment discharge damper 13, and the blower14, so that the interior temperature of the temperature switchablecompartment 3 is maintained at a preset temperature.

Above the heater 15, a temperature sensor 24 is arranged adjacent to theheater 15. The temperature sensor 24 is firmly attached on the ceilingface of the part of the rear panel 33 so bent as to enclose the heater15. Thus, the temperature closely above the heater 15, where heatingproceeds fastest with the rising stream of air heated by the heatradiating from the heater 15, is detected by the temperature sensor 24.

When the temperature sensor 24 finds the temperature in the vicinity ofthe heater 15 to be abnormally high, the heater 15 is de-energized. Inthis way, it is possible to prevent the heater 15 and the componentsaround it from breaking, burning, or smoking. Furthermore, above thetemperature sensor 16, a thermal fuse 30 is arranged. The thermal fuse30, when the temperature thereof becomes as high as a predeterminedlevel, melts so that the heater 15 is de-energized. This furtherimproves safety.

FIG. 6 is a vertical sectional view, as seen from the front, of themiddle portion of the refrigerator 1. The cold air path 31 behind thefreezer compartment 6 has an opening formed at upper front of the blower18, and the blower 18 sends air into the ice-maker compartment 4. In abottom portion of the freezer compartment 6, which communicates with theice-maker compartment 4, there is arranged a freezer compartment damper22. Behind the freezer compartment 6, at the bottom thererof, there isarranged an air return path 21 (see FIG. 3) that leads air through thefreezer compartment damper 22, to the evaporator 17, and then back tothe cold air path 31. The amount of air led out of the freezercompartment 6 is controlled by opening and closing the freezercompartment damper 22.

At the top thereof, the cold air path 31 communicates with the cold airpath 32 via the cooling compartment damper 27. The cold air path 31 alsobranches into the air introduction path 12, so as to communicate, on onehand, with the chilling room 23 via the chilling compartment damper 25and, on the other hand, with the temperature switchable compartment 3via the temperature switchable compartment discharge damper 13 asdescribed above.

In the cooling compartment 2, in a rear bottom portion thereof, there isformed a cooling compartment outlet port (not shown). In the vegetablecompartment 5, a vegetable compartment inlet port (not shown) is formed.The cooling compartment outlet port and the vegetable compartment inletport are coupled to each other via a path (not shown) located behind thetemperature switchable compartment 3, and thereby the coolingcompartment 2 communicates with the vegetable compartment 5.

The air return path 19 that communicates with the temperature switchablecompartment 3 extends downward from the temperature switchablecompartment return damper 20 to run behind the temperature switchablecompartment 3 and the vegetable compartment 5. By opening and closingthe temperature switchable compartment return damper 20, the air in thetemperature switchable compartment 3 is led to the evaporator 17 throughthe air return paths 19 and 21. In the rear face of the vegetablecompartment 5, there is formed a vegetable compartment outlet port (notshown) that communicates with the air return path 19.

FIG. 7 is a cold air circuit diagram showing how cold air flows in therefrigerator 1. When the blower 18 is operated, the cold air produced atthe evaporator 17 rises through the cold air path 31 as indicated byarrow A (see FIG. 6), and is supplied to the ice-maker compartment 4.The cold air supplied to the ice-maker compartment 4 flows through theice-maker compartment 4 and the freezer compartment 6, and then flowsout via the freezer compartment damper 22 to return to the evaporator 17through the air return path 21. In this way, the ice-maker compartment 4and the freezer compartment 6 are cooled.

When the blower 28 is operated, part of the cold air branches off thecold air path 31 at the top thereof to flow into and through the coldair path 32 as indicated by arrow B (see FIG. 6) via the coolingcompartment damper 27, and is sent to the cooling compartment 2; thatpart of the cold air also flows into and through the air introductionpath 12 as indicated by arrow C (see FIG. 6), and is then supplied tothe chilling compartment 23. The cold air sent into the coolingcompartment 2 and the chilling compartment 23 flows through them andthen flows into the vegetable compartment 5. The cold air that hasflowed into the vegetable compartment 5 flows therethrough and thenflows through the air return paths 19 and 21 back to the evaporator 17.In this way, the cooling compartment 2 and the vegetable compartment 5are cooled. When the preset temperatures are obtained, the coolingcompartment damper 27 and the chilling compartment damper 25 are closed.

When the blower 14 is operated, part of the cold air branches off thecold air path 31 at the top thereof to flow through the air introductionpath 12 into, as indicated by arrow D (see FIGS. 4 and 6), thetemperature switchable compartment 3 via the temperature switchablecompartment discharge damper 13. The cold air that has flowed into thetemperature switchable compartment 3 flows therethrough, then flows outthereof through the outlet port 33 b, and then returns to the evaporator17 through the air return paths 19 and 21 as indicated by arrow E (seeFIGS. 4 and 6). Thus, the inside of the temperature switchablecompartment 3 is cooled.

As described above, the interior temperature of the temperatureswitchable compartment 3 can be switched by the user as he/she desires.For example, the user can select any temperature zone from among thoseintended for freezing (−15° C.), partial freezing (−8° C.), chilling(−3° C.), cooling (3° C.), vegetable (8° C.). This enables the user tokeep articles in frozen or cool storage at the desired temperature. Theswitching of the interior temperature of the temperature switchablecompartment 3 can be achieved by changing the degree to which thetemperature switchable compartment discharge damper 13 is opened or theamount of air supplied from the blower 14.

In that case, as shown in FIG. 4, the double-sided baffle 20 a of thetemperature switchable compartment return damper 20 is so located thatit keeps the air return path 19 open and the communication path 36closed. Hence, the cold air that flows in via the inlet port 33 a flowsvia the temperature switchable compartment return damper 20 into the airreturn path 19, without circulating through the communication path 36.This prevents the cold air from being short-circuited through thecommunication path 36 and thereby improves the efficiency of the blower14.

When, for example, the interior temperature of the temperatureswitchable compartment 3 is switched from the “freezing” to the“cooling” zone, the temperature may be raised by energizing the heater15. This allows quick switching of the interior temperature of thetemperature switchable compartment 3 to a desired one. Furthermore, byenergizing the heater 15, the interior temperature of the temperatureswitchable compartment 3 can be switched from the cold setting forfrozen or cold storage of articles to the hot setting for temporarystorage of cooked food, warm storage of food for cooking purposes, andthe like.

When the interior temperature of the temperature switchable compartment3 is at the hot setting, as shown in FIG. 5, the temperature switchablecompartment discharge damper 13 is closed and the double-sided baffle 20a of the temperature switchable compartment return damper 20 ispositioned such that it keeps the air return path 19 closed and thecommunication path 36 open. When the heater 15 and the blower 14 areoperated, the air sent by the blower 14 as indicated by arrow F flowsthrough the communication path 36 via the outlet port 33 b as indicatedby arrow G.

Thus, the air in the temperature switchable compartment 3 is circulatedby being led to the blower 14 via the temperature switchable compartmentreturn damper 20 as indicated by the dotted line S in FIG. 7. This makesit possible to keep the temperature switchable compartment 3 airtightand thereby to prevent the warm air therein from escaping. Hence, it ispossible to produce an even temperature distribution inside thetemperature switchable compartment 3 at the hot setting and to preventthe heater 15 and the components around it from deforming, burning, orsmoking. Moreover, it is possible to realize a refrigerator that iseconomical to the user by eliminating the need for a separatewarm-keeping box or the like for keeping cooked food warm and that isuseful by eliminating the need for securing a space for such awarm-keeping box or the like.

It is preferable that the interior temperature of the temperatureswitchable compartment 3 at the hot setting be kept at 50° C. or more.This is in consideration of the fact that common microorganisms causingfood poisoning grow at 30° C. to 45° C., and also in consideration ofthe permitted tolerance in the heater capacity, the temperaturedistribution inside the temperature switchable compartment 3, and otherfactors. This helps prevent growth of microorganisms. It is preferable,however, that the interior temperature of the temperature switchablecompartment 3 at the hot setting be kept at 80° C. or less. Thiscontributes to low cost, because resin components commonly used inrefrigerators are resistant up to 80° C.

Microorganisms causing food poisoning are killed by heat; for example,enterohaemorrhagic Escherichia coli (e.g., E. coli O157) are killed whenkept at 75° C. for one minute. In consideration of this, and also inconsideration of the permitted tolerance in the heater capacity and thetemperature distribution inside the temperature switchable compartment3, it is particularly preferable that the interior temperature of thetemperature switchable compartment 3 at the hot setting be kept at 80°C.

Here are the results of a test on how the numbers of food poisoningmicroorganisms decrease when kept at 55° C. A test sample was preparedthat in its initial state included 2.4×10³ CFU/mL of Escherichia coli,2.0×10³ CFU/mL of Staphylococcus aureus, 2.1×10³ CFU/mL of Salmonella,1.5×10³ CFU/mL of Vibrio parahaemolylticus, and 4.0×10³ CFU/mL ofBacillus cereus. The test sample was first heated from 3° C. to 55° C.over 40 minutes, was then maintained at 55° C. for 3.5 hours, and wasthen cooled from 55° C. to 3° C. over 80 minutes; then the number of themicroorganisms were counted again. It was found that the number of anyof the kinds of microorganism tested had decreased to 10 CFU/mL or less(i.e., below the detectable level). This demonstrates that keeping thetemperature switchable compartment 3 at 55° C. at the hot settingprovides a sufficient effect of reducing microorganisms.

As described above, the heater 15 is a heat-radiating glass-tube heater.The heater 15 may be a heat-conducting heater such as a sheet-shapedaluminum-deposited heater, which is inexpensive but has a low heatingrate. For this reason, with a heat-conducting heater, when thetemperature switchable compartment 3 is at the hot setting, the interiortemperature thereof takes a long time to pass through the temperaturerange from 30° C. to 45° C., in which microorganisms actively grow,leading to low safety in terms of food hygiene. A higher heating ratecan be achieved by increasing the heater capacity; this, however, cannotbe done above the temperature (normally, about 80° C.) up to which thecomponent to which the heater is attached is resistant; moreover, doingso may make the heat-radiating surface so large that it extends up to afront part of the temperature switchable compartment 3, increasing therisk of the user getting burned.

By contrast, a heat-radiating glass-tube heater has a high heating rate,which contributes to safety in terms of food hygiene. Furthermore, evena high-capacity heat-radiating glass-tube heater occupies only a smallarea of space, and thus, as shown back in FIG. 4, it can be arranged ina rear portion of the temperature switchable compartment 3, and thisreduces the risk of the user getting burned. Therefore, it is morepreferable that the heater 15 be a heat-radiating glass-tube heater.

The heater 15 is capable of being operated at an heat output higher thanis needed to maintain the interior temperature of the temperatureswitchable compartment 3 at the hot setting, in which cooked food arekept warm. The heat output of the heater 15 can be changed by changingthe energization rate of the heater 15. Hence, rapid switching of theinterior temperature of the temperature switchable compartment 3 fromthe cold setting to the hot setting can be achieved by operating theheater 15 at a high heat output, and this makes the refrigerator 1useful. When the interior temperature of the temperature switchablecompartment 3 reaches a preset hot-setting temperature, it can bemaintained at the preset temperature by operating the heater 15 at alower heat output.

For example, when, as the heater 15, a heater whose power consumption isabout 190 W and whose surface area is about 10,990 mm² is used andoperated at an energization rate of 100%, the interior temperature of atemperature switchable compartment 3, when it has a volume of about0.023 m³, can be raised from 3° C. up to 80° C. in about 30 minutes.Then, by operating the heater 15 intermittently at an energization rateof 15% (ON for 15 seconds and OFF for 85 seconds), the interiortemperature of the temperature switchable compartment 3 can be keptabout 80° C. The blower 14 has a motor equipped with an axial flow fan,and is operated so as to send air approximately at a rate of 0.4 m³/m.

Here, while the temperature is kept constant, the surface temperature ofthe heater 15 remains not higher than 250° C., and thus below theignition point (494° C.) of isobutane, which is a flammable refrigerant.Thus, when, out of consideration of the environment, isobutane, which isa flammable refrigerant, is used as the refrigerant sealed in therefrigeration cycle, even if isobutane leaks from the evaporator 17 orelsewhere, there is no risk of the heat from the heater 15 causing anexplosion. This makes the refrigerator 1 safer to the user.

In the present embodiment, when the interior temperature of thetemperature switchable compartment 3 has reached a predeterminedtemperature at the cold setting, the air inside the temperatureswitchable compartment 3 may be circulated. Specifically, with thetemperature switchable compartment return damper 20 so located as tokeep the air return path 19 closed and the communication path 36 open,and with the temperature switchable compartment discharge damper 13closed, the blower 14 is operated. This makes it possible to produce amore even temperature distribution inside the temperature switchablecompartment 3 at the cold setting.

Instead of opening and closing the air return path 19 and thecommunication path 36 with the temperature switchable compartment returndamper 20, the air introduction path 12 and the communication path 36may be opened and closed with the temperature switchable compartmentdischarge damper 13. This can be achieved by providing the temperatureswitchable compartment discharge damper 13 with a double-sided bafflesimilar to the one provided in the temperature switchable compartmentreturn damper 20.

When the double-sided baffle is positioned so as to keep the airintroduction path 12 open and the communication path 36 closed, the coldair that has flowed into the temperature switchable compartment 3 viathe inlet port 33 a flows out thereof via the outlet port 33 b, and isled to the air return path 19 via the temperature switchable compartmentreturn damper 20. On the other hand, when the baffle is positioned so asto keep the communication path 36 open and keep the air introductionpath 12 closed, the air circulates inside the temperature switchablecompartment 3. This makes it possible to reduce the cost of therefrigerator 1 and to improve the volume efficiency thereof aseffectively as in the case described above.

A damper may be provided at the outlet port of the vegetable compartment5. In this case, when the temperature switchable compartment 3 isswitched from the hot setting to the cold setting, closing theabove-mentioned damper makes it possible to prevent the hot air in thetemperature switchable compartment 3 from flowing back into thevegetable compartment 5. In addition, it is possible to prevent the coldair in the vegetable compartment 5 from reaching the double-sided baffle20 a and causing condensation thereon.

The freezer compartment damper 22 is closed if, when the temperatureswitchable compartment 3 is switched from the hot setting to the coldsetting, the blower 18 is not operated. This prevents the hot air in thetemperature switchable compartment 3 from flowing back into the freezercompartment 6 as the blower 14 is operated.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a refrigerator provided with atemperature switchable compartment whose interior temperature can beswitched by the user. The present invention is also applicable to arefrigerator provided with, at the cold air inlet side of a storagecompartment, a damper for opening and closing a cold air path.

1. A refrigerator in which cold air produced by a cooling device issupplied to a: storage compartment through a cold air path, wherein adamper for varying an amount of cold air supplied to the storagecompartment is arranged in the cold air path, and the damper includes anopening that communicates with the storage compartment and a movablebaffle that is arranged on a cooling device side of the opening so as toopen and close the opening.
 2. The refrigerator of claim 1, wherein thestorage compartment is a temperature switchable compartment whoseinterior temperature can be switched among more than one alternatives,and a cooling compartment is provided that is arranged parallel with thestorage compartment so as to receive cold air through a path branchingoff the cold air path.
 3. The refrigerator of claim 2, furthercomprising a heater for raising the interior temperature of thetemperature switchable compartment, wherein, with the heater operated,the interior temperature of the temperature switchable compartment canbe switched to a hot setting for keeping cooked food warm.
 4. Therefrigerator of claim 1, wherein the baffle is swingably supported by apivot shaft extending horizontally along a top end of the baffle.
 5. Therefrigerator of claim 1, wherein a heat insulator is provided on asurface of the baffle.
 6. The refrigerator of claim 1, wherein, at a rimof the opening, at a side thereof opposite from the baffle, there isformed a step lower than the opening or a slope slanting downward fromthe rim of the opening.